Efforts to reduce harmful emissions from diesel engines may include reducing CO emissions, unburned hydrocarbons, particulate emissions, and NOx emissions. Measures to reduce one class of emissions may make efforts to reduce others more challenging. For example, running a diesel engine with a lean burn air-to-fuel ratio may increase soot combustion and reduce the level of unburned fuel in the exhaust. However, the excess air in the lean mixture may tend to increase the amount of NOx produced. Conversely, effective techniques to reduce NOx may allow for more aggressive soot combustion. This interdependence, may further increase the importance of NOx reduction measures.
Measures to reduce NOx, may include selective catalytic reduction (SCR). SCR systems may spray, or inject a Diesel Exhaust Fluid (DEF) in regulated doses into the exhaust stream upstream from an SCR catalyst. DEF is typically a 32.5% solution of urea in demineralized water. DEF products may be known commercially as DEF, AdBlue, urea, ARLA, or ARNOX. Once sprayed, or injected, into the exhaust stream the urea may decompose into ammonia and carbon dioxide. Then, within the SCR catalyst, the NOx may be chemically reduced by the ammonia (NH3) into water (H2O) and nitrogen (N2), and released through the exhaust.
The DEF may be stored in a container located onboard diesel powered vehicles. The container may be located in the engine compartment. Engine compartments typically also include storage systems for other liquids for engine and vehicle operation, for example, hydrocarbon materials such as fuels, oils, other lubricants, additives, etc. Because of their relative proximity cross contamination is possible. Avoiding contamination of the reductant fluid, i.e. the DEF, is important for a number of reasons. For example, if contaminated: the effectiveness of reducing NOx with the DEF may be reduced; the remaining DEF may be consumed more quickly than it would otherwise be consumed; the contaminated DEF may cause the SCR system to malfunction, and may damage the engine's exhaust management equipment; and a malfunctioning SCR system may cause the engine to shut down, or cause a vehicle equipped with the system to operate at very slow speeds. In addition, the presence of the contamination in the DEF storage tank may void the equipment manufactures warranty. Once the hydrocarbons are in the reductant system the system may have to be, replaced or, taken apart, cleaned, and rebuilt with some new, and typically expensive, components to replace those that may be destroyed.
Ancillary diesel support systems, such as refueling stations, refueling vehicles, retailers, and various maintenance facilities may include reductant storage, and distribution, systems. These too, may be vulnerable to contamination. Typically these storage systems and other parts of reductant dosing systems are made with materials which may degrade in the presence of hydrocarbons.
Owners and users are warned not to put any products not identified as approved reductants into the DEF system. Warranty agreements may include a warning or clause that the warranty will not cover such misuse/abuse from contaminant introduction. Determining who is responsible for contamination of the DEF, and perhaps for the cost of remediation/repair, and avoiding possible, or further, damage would be advantageous. Also advantageous would be providing early notification of the contamination which may avoid damage, or extensive remediation efforts.
Methods exist to test for hydrocarbons in the reductant fluid. For example, US Patent publication 20130115137 A1 discloses sensing materials for selective and sensitive detection of hydrocarbons suggested implementation via a wearable detector. As another example the firm Bellingham and Stanley make such a product in the form of a test strip that is effective in giving such proof of contamination.
The inventors of the present disclosure have recognized a number of shortcomings of these approaches. For example, the wearable detector disclosed 20130115137 A1 is too far removed from the location of the possible contamination. The problem with the test strips is that the strip must be put into the fluid of the tank or a sample of the fluid must be brought out of the tank in order to test the fluid. Often reductant storage tanks have a long fill pipe, especially those on vehicles. This makes such testing difficult or impossible and so the suspected system must be removed and opened in order to complete the test. This removal and opening of the system is difficult and expensive in itself.
What is needed is an indicator, a system and a method that makes contamination easy to determine and that can be accomplished in close proximity to the DEF storage tank. Embodiments in accordance with the present disclosure provide a system, method and apparatus for making evident, diesel exhaust fluid (DEF) contamination is provided. The system, for use with a diesel exhaust fluid system, may include a container having an opening to receive a diesel exhaust fluid. A reactive device may be located near the opening and reactive upon exposure to one or more predetermined components potentially present in a fluid pourable into the container through the opening. The reactive device may not be reactive to the diesel exhaust fluid.
In this way, contamination, or lack of contamination, may be determined substantially immediately and at the site of the DEF storage tank. Also in this way, a servicing organization that suspects hydrocarbon contamination could confirm the contamination before they work on the system.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or is that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.